The nanoimprinting technique, which is a fine processing technique, is a technique for forming a pattern by using a mold member (imprint mold) in which a fine uneven pattern is formed on the surface of a base material, and transferring the fine uneven pattern onto a workpiece such as an imprint resin to thereby same-size transfer the fine uneven pattern (see Patent Document 1). In particular, the nanoimprint technique has been increasingly attracting attention in the field of semiconductor device fabrication processes as the miniaturization of wiring patterns or the like in semiconductor devices have been further progressing.
In the imprint molds used in such nanoimprint technique, a fine uneven pattern (main pattern) for fabricating, for example, a wiring pattern in a semiconductor device is formed on a pattern formation surface. Then, a fine uneven pattern (dummy pattern, alignment mark, etc.) of a size larger than that of the main pattern is typically also formed on the pattern formation surface with the object of facilitating the release of the imprint mold and aligning the imprint mold with the transfer substrate such as a semiconductor substrate during the imprint processing. Along with the progress in the miniaturization of semiconductor devices produced by nanoimprinting using such imprint molds, the size of the main pattern in the imprint molds has been reduced to less than several tens of nanometers.
With the subsequent progress in miniaturization of semiconductor devices, the technological development advances in the direction of further reducing the size of the main pattern in the imprint molds, and a method for processing a base material for an imprint mold by using a sidewall pattern formed by the so-called sidewall process has been suggested as a method for producing an imprint mold in which a fine-size main pattern and a dummy pattern or an alignment mark which is larger in size than the main pattern are formed in the pattern formation surface (see Patent Document 2).